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Data from NASA Apollo 11 Press Kit Shows spacecraft weight delivered to LEO (Low Earth Orbit) Shows weights for each portion of Apollo 11 Command & Service Module L.E.M. (Descent and Ascent stages) Various sub-systems (water, ECS package, etc.)
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Data from NASA Apollo 11 Press Kit • Shows spacecraft weight delivered to LEO • (Low Earth Orbit) • Shows weights for each portion of Apollo 11 • Command & Service Module • L.E.M. (Descent and Ascent stages) • Various sub-systems (water, ECS package, etc.) • Propellant weights for each stage, engine specs • Allows calculation of “Parametric” values
Trans Lunar Injection Summary • Total vehicle weight in LEO = 296,379 pounds • Total propellant weight = 157,010 pounds • Stage 3 engine - one J-2 using Lox/LH2 • Command/Service Module weight = 67,164 pounds • Lunar Excursion Module weight = 33,205 pounds • Total Weight delivered to Low Lunar Orbit • = 100,369 pounds • Lunar Orbit Weight Fraction = .33 • So, for every 10,000 lbs in LEO, Saturn put 3300 lbs in LLO • (using LOX/LH2 J-2 class engines)
Trans Lunar Injection Summary • For every 10,000 lbs in LEO, we can put 3300 lbs in LLO • Requires LOX/LH2 J-2 class engines • Limited amount of time from launch to TLI burn • Not generally used for shuttle-based upper stages • Good for un-manned launches, like Delta’s II thru IV • Other propellants (MMH/NTO4), deliver lower performance • Isp LH2 = 450 Isp MMH = 338 • MMH/NTO4 can be stored for longer periods • Used for CSM & LEM engines • For MMH engines, 10,000 lbs LEO puts 1125 lbs in LLO
Current Launchers Improvements • Delta II (7925H-10L) can place 10,120 lbs in LEO • Current MB-60 engine is higher performance than J-2 • Isp = 467 versus Isp = 420 for J-2 • Required propellant = 10,120*.666*(420/467) = 6019 lbs • Payload to LLO = 10,120-6019 = 4101 lbs (extra 761#) • Good for launching cargo, supplies, etc. • Delta IV (5,4) can place 25,300 lbs in LEO • Propellant = 15,048 lbs • Payload to TLI = 10,252 lbs
Lunar Orbit Insertion • Apollo Summary • Command Service Module/LEM weight at TLI = 100,369 • LOI Propellant used = 12,011 lbs MMH/NTO • Apollo Isp = 318 versus Isp = 338 for RS-72 • Fuel fraction = .112 ……. Payload fraction = .887 • Delta II (TLI = 4101 lbs) payload to LLO = 3,639 lbs • Delta IV (5,4)(TLI = 10,252) payload to LLO = 9,099 lbs
Lunar LANDING • Apollo Summary • LEM weight 33,205 (Apollo 11) • Descent Propellant used = 18,100 lbs MMH/NTO • Payload to Lunar Surface = 14,501 lbs …. • Apollo Isp = 318 versus Isp = 338 for RS-72 • Apply to LEM weights, current fractions are … • Fuel fraction = .513 ……. Payload fraction = .487 • Delta II (LLO = 3639 lbs) payload to Lunar Surface = 1,772 lbs • Delta IV (5,4)(LLO = 9,099) payload to LLO = 4431 lbs !!!!